Glass Stories

Glass and Resonancethe mouse. This information is analyzed by a DSP
We have all heard stories of how opera singers(Digital Signal Processor), which is used to detect
can shatter glass upon hitting a particular note.imperfections in the underlying surface, and
However, how plausible is this notion? In order todetermine motion. Some materials, such as glass,
shatter glass, a singer's voice has to be able tomirrors or other very shiny, uniform surfaces
match the frequency of the glass. (Every objectinterfere with the ability of the DSP to analyze
has a resonant frequency, which is the naturalthe surface beneath the mouse. Since glass is
frequency at which an object vibrates.) If youtransparent and uniform, the mouse is unable to
blow on the edge of a glass, you will hear apick up enough imperfections in the underlying
resonant hum, and if you keep blowing, you cansurface to determine motion.
even create a tune - this sound is the uniqueMirrored surfaces are also a problem, since they
resonant frequency of the glass.constantly reflect back the same image, causing
The singer would have to sing very loudly:the DSP not to recognize motion properly. When
precisely producing a note of about 135 decibles,the system is unable to see surface changes
which is more sonic boom than pertaining toassociated with movement, the mouse will not
anything musical. The human threshold for pain iswork properly.
about 120 decibels. The note would have to beGlass and Household
maintained for the duration of at least two toCleaning glass is the big 'bug bear' of most
three seconds for the right vibration to build up,homeowners! The endless build up of soap scum
so the glass could shatter. In the late 70s,lurking on your tiles and soap racks, and the
laboratory experiments with a professionalsoapy film on shower doors is like the invasion of
soprano and a trumpet player showed thatAlien 5! Here are a few handy hints on how to
neither could shatter glass. The only singer whokeep the alien out of your home.
has apparently succeeded is the famed tenor,Some say that the best way to get the film off
Enrico Caruso, but the validity of this claim is aglass doors is to use a no-wax floor cleaner. All
matter of conjecture.you do is wipe it on and make sure you clean it
Glass and Wineoff very well. Vinegar is a close second - you can
Why do wine glasses have such long stems?also add vinegar to your dishwasher or sink, which
Wine enthusiasts proclaim that it is essential inwill get rid of any soap residue and give your
order to prevent the heat of one's hand on thedishes an extra sparkle.
glass from warming the wine. Any drink that isAmmonia can also clean glass. You can also
chilled should be in a glass with a stem. Equallymake your own ammonia solution by combining
important is the aesthetics of a fine stem, whichammonia and water. Use a spray bottle and spray
enhances the pleasure of the experience.directly onto the surface. Use a sponge or
By contrast, fine scotch or cognac is drunk fromstiff-bristled brush to scrub affected areas. Wipe
a snifter glass, which has a short stem. The stemclean, and rinse well. Newspaper has enough
in the snifter should be wedged between one'sfriction to clean the gunk off and is smooth
middle and ring finger, with the palm and fingersenough to act as a cleaning cloth.Let soap scum
wrapped around the bowl of the glass, to gentlybuildup on glass be a thing of the past. Pilkington
warm the whisky/brandy and allow the aromasGlass has brought out a self-cleaning glass,
to come to the fore.guaranteed to rock the world of any homeowner.
Glass and ComputersThis innovative product, conceived by the
Anyone who uses a computer knows that anworld-leaders in glass making, meets all the
optical mouse does not work on a glass table!relevant international standards, and is able to
Because optical mice use an LED and a camera toperform in extreme conditions.
rapidly, capture images of the surface beneath